* {
    margin: 0;
    padding: 0;
}

body {
    width: 100%;
    height: 100vh;
    background-color: #333;
    display: flex;
    justify-content: center;
    align-items: center;    
}

.main {
    width: 40vw;
    height: 40vw;
    position: absolute;
    display: flex;
    justify-content: center;
    align-items: center;
}

.main span {
    --bg: black;
    --sg: transparent;
    position: absolute;
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: flex-start;
}

.main span::after {
    content: '';
    width: 0.5vw;
    height: 2vw;
    position: absolute;
    background-color: var(--bg);
    box-shadow: 0 0 0.5vw var(--sg), 0 0 1vw var(--sg), 0 0 2vw var(--sg);
    transition: 0.8s linear;
}

input[type='range'] {
    --c: #1e90ff;
    width: 40vw;
    height: 1vw;
    position: absolute;
    transform: translateY(25vw);
    appearance: none;
    background: linear-gradient(var(--c), var(--c)) no-repeat, black;
    background-size: 0 100%;
    border-radius: 0.5vw;
}

input[type='range']::-webkit-scrollbar-thumb {
    appearance: none;
    width: 2vw;
    height: 2vw;
    background-color: var(--c);
    border-radius: 50%;
    box-shadow: 0 0 1vw white, 0 0 2vw white;
}

#percentage {
    color: white;
    font-size: 10vw;
    font-family: Arial, Helvetica, sans-serif;
    text-shadow: 0.2vw 0.2vw 0 gray, 0 0 1vw #1e90ff, 0 0 2vw #1e90ff, 0 0 4vw #1e90ff;
}
